Automatic stack-lifting device



Dec.11,1928. 1,695,233

. H. A. FINK I AUTOMATIC STACK LIFTING DEVICE Filed Jan. 14, 1928 4Sheets-Sheet I Iva/awn- H. A. FINK AUTOMATIC STACK LIFTING DEVICE Dec.11, 1928. 1,695,233

Filed Jan. 14, 1928 v 4 Sheets-Sheet 2 Dec. 11, 1928. 1,695,233

H. A. FINK AUTOMATIC STACK L'IFTING DEVICE Filed Jan. 1.4, 1928 4Sheets-Sheet 3 Patented Dec. 11, 1928 PATENT OFFICE.

HENRY A, FINK, OF CHICAGO, ILLINOIS, ASSIGNOR T CONTINENTAL CAN COMPANY,

IN (3., OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

AUTOMATIC STACK-LIFTING DEVICE.

Application filed January 14, 1928. Serial No. 246,842.

This invention relates to sheet feeding mechanism and more particularlyto the stack controlling portion thereof.

Many types of devices have heretofore been 0 proposed for taking a sheetfrom a stack and delivering it to a machine which operates upon thesheet. The present device is CQI1- cerned with an automatic mechanismfor controlling the lifting of the stack after a u) sheet has beenremoved therefrom, so that the upper surface of each successive topsheet of the stack is brought to approximately the same position forengagement by the feeding of their movement, and thereafter the stackelevating mechanism is thrown out of operation for the remaining portionof the move- 80 ment of the sheet lifting devices; so that when thesheet lifting devices are employed to actuate the controlling means, theelevation of the stack occurs while the lifting devices,

are in contact with the top sheet.

Still another feature of the invention is the provision of a stackelevating mechanism employinga ratchet and roller mechanismforelevating, the pawl for the ratchet bein normally out of engagementtherewith, an only brought into engagement therewith when it p isnecessary to lift'the stack: so that when the mechanismis, so to speak,de-energized,

i. e., when it is no longer necessary to lift the stack, the partsautomatically return to an inoperative position.

With these and other objects in view as will appear in the course of thefollowing specification and claims, one form of execution of theinvention has been represented by way of illustration on theaccompanying drawings, in

which:

Figure 1 is a front elevation of a sheet feedare provided with rollers 1ing mechanism having'the present invention embodied therein. I

Fig. 2 is an elevation of the right hand end of this machine. i

Fig. 3 is an elevation of ofthis machine.

Fig. 4 is a detailed;vi ew in fra mentary the left hand end frontelevation on an enlarged sca e, of the controlling elements. p p

Fig. 5 is a fragmentary side elevation showing in detail the pawlandratchet advancing mechanism with associated throw-out.

In these drawings, thereis represented a sheet feeding mechanism used inconjunction with a sheet slitter, by way of illustration of theemployment of the sheet feeder in conjunction with a single drive forthe feeding of the slitting machine.

The sheet feeder includes a platform to re ceive a stack of sheets, anda sheet removing device for taking the top sheet of the stack anddelivering it to theslitting machine. The illustrated form of sheethandling device is a suction,cup which is periodically raised 4 andlowered. In the lowered position the cup is intended to engage thetopmost sheet, then to raise the sheet and to deliver it to advancingmeans which delivers it to the slitting machine. Devices driven from themain drive are employed to raise the platforn'nv s termittently andcooperate with the sheetlifting devices so that the platform is raisedin proportion to the withdrawal of sheets from the top of the stack, sothat the top of the stack is maintained substantially at a predeterminedlevel. I

The sheet feeding-machine includes standards 10 which at the .upper endcarry an out standing bracket 11 that in turn supports the journalmembers 12 of a rotatable shaft 13. Mounted for vertical slidingmovement in the guides 14 of the bracket 11 are the plungers 1 15 whichcarry at their lower ends the suction cups 16. At the upper ends, theplungers 15 Fixedly mounted on the shaft 13 are earns 18 for engagementwith the respective rollers 17, so that during the rotation of the shaft13 the cams move therewith, and thus the rollers and plungers 15 aremoved upward so that the suction cups 16 are raised, and by the weightof these members the" rollers 17 are drawn downward again and maintainednormally clockwise movement of the lever 20 and spring 22, to engage andestablish electrical conductive relationship with a fixed contact 24carried on an insulating standard 25 of the bracket 11. It will be notedthat upon a given downward movement of the plunger 15 the pin 19 willrock the lever 20 in a counterclockwise direction and thus make anelectrical contact between the members 23 and 24.

The shaft 13 likewise carries suitable mechanism such as an eccentricand strap to actuate a rock lever 26 which is pivoted on an auxiliarybracket 27 of the main bracket 11, and at its lower end carriesmechanisms indicated generally by S for the purpose of taking the sheetwhich has been raised by the suction cup 16 and delivering it into asuitable sheet working machine such as the slitter M. These devices andthe machine may be of any well known type and operation.

On the frame 10 is likewise journaled a shaft L having an eccentric 29thereon embraced by the eccentric strap 30, which is mounted on the endof an eccentric rod 31. A transverse shaft 32 is journaled in both framememberslO and extends at one end' through the frame member and carrieskeyedthereon a ratchet wheel 33, and in addition thereto a rockercomp-rising the counterweight portion 34 and the two arms 35, 36.

The arm 35 is connected bya pivot 37 with the eccentric rod 31: whilethe arm 36 has a pivot 38 to support a pawl 39 which is presented forengagement with the teeth of the ratchet wheel 33. The counterweight 34has an arcuate slot 40 in which a heavy bolt 41 may be moved and clampedfor the accurate adjustment of the counterweight effect.

A bracket 42 of a frame member 10 supports an electromagnet 43 having amovable plunger 44 carrying the pivoted connection link 45, which inturn is pivoted to the lever 46. This lever 46 has an adjustablecounterweight 47 at its end to cause it to normally rock in acounterclockwise direction about its pivot 48 on the frame 1O.v The endof the lever 46 beyond the pivot 48 has an arcuate upper surface 49 andan extending end finger 50 which is adapted to be limited in itsmovement and therewith to determine the end positions of the engagementwith the stop pins 51 and 52 of whole lever by respective the respectivebevel gears 64 keyed to the I transverse shaft 32. It is preferred toprovide a hand wheel 61 on the upper end of one of the screws 61 so thatthe stack may be raised and lowered by hand.

A chain drive is provided between sprockets on the shaft 13 and theshaft L, and a similar chain drive 71 is provided between a sprocket onthe shaft Land a shaft 72 of the machine M, which in turn is driven fromthe main drive shaft 73 of the latter through a clutch member 74, whichis actuated by a forked clutch rod 75. This clutch rod ispivotallyconnected to a link 76 which is guided in a standard 10 of themachine, and carries the upwardly extending fingers 77 which are adaptedin their movement to en gage and actuate the finger 78 of a tumblerswitch 79. It willbe understood that when the clutch lever is moved toconnect the main shaft 73 for power driving, the link 76 at the sametime moves the tumbler switch 79 so that.power is furnished to theelevating control mechanism, as will be described hereinafter: and viceversa when the lever 75 is moved to disconnect the power drive from themachinery, the tumbler switch 79 opens this circuit. In this way, thecontrol system and themachines are made ready for operation and aredisconnected simultaneously.

The electrical connections comprise the conductors 81 leading from asource of electric current, such as the lighting means, through theswitch 79 to the electroma net 43 and to the contacts 23, 24, so that wen the switch 79 is closed the circuit through the electromagnet 43 isopened only at the contacts 23, 24.

The method of operation of the structure is as follows: When a bale ofsheets has been laced upon the table 20 and has been raised by the handwheel 61 to the approximate height for lifting, and the clutch lever 75has been moved to deliver power to the drive shaft 72 and to close thetumbler switch 79, the shafts L and 13 are simultaneously driven. Theplungers 15 are moved up and down by the engagement of the rollers 17with the surface of the cams 18, and by the usual well known means thesuction cups 16 are cvacuated at the proper moments to seize the topmostsheet ofthe stack if this stack is engaged by the cups. Then during afurther rotation of the shaft 13 and the cams 18 this sheet is raisedaway from the stack, and then by means of an eccentric on shaft 13, thelever 26 is actuated to move the parts S to receive this sheet anddeliver it to the slitting machine N in known manner. v

As successive sheets are takenv from the stack, the height of the latterabove the prevailing position of the platform is decreased, untilfinally the permissible travel of the cups 16 is no longer suflicient toseize a sheet by the suction effect and to deliver it properly to theadvancing devices S. When,

however, the plungers 15 have been moved downward for more than apredetermined maximum distance, the pin 19 has engaged the lever 20 androcked about its pivot near the bottom of the stroke'of the plungers 15,so that contact is established between the points 23, 24, therebyclosing the electrical circuit above referred to and energizing theelectromagnet 43.

This electromagnet attracts its core andtherewith rocks the lever46clockwise about its pivot 48, causing the arcuate surface 49 to movedownwarduntil the finger 50 is engaged against stop-pin 52. 'The surface49 no longer supports thejpin 53 of the pawl 39, and the latter fallsinto engagement with the teeth of the ratchet, ,wheel 33. During thewhole rotation of the shaft 13, the shaft L has been revolving anddriving its eccentric 29, so that the eccentric; rod 31'has been rockingthe lever and counterweight system 34, 35, 36 continuously, but withouteffect upon the ratchet wheel 33 solong as the pawl 39 is held out ofcontact with the teeth thereof. Since now the pawhis inengagement withthese teeth, the downward movementof-the eccentric rod 31 causes thepawlto clock freely over the teeth in one direction, and the vupwardmovement of the eccentric rod 31 causes the pawl to advance the ratchetwheel 39 in a counterclockwise direction in Fig. 2,

thus rotating shaft 32 and therewith the screws 62. and raising thetable 61. The stack of sheets'is therefore raised while the suction cups16 are in the lowered position, and after the stack has been raised by adistance sufiicient to lift the plungers 15 until the pin 19 is nolonger engaged with the lever 20, the contact will be broken at points23, 24 the electromagnet 43 deenergized, and the lever 46 will rockabout its pivot under the action of the counterweight 47. so thatthepawl 39 is once more raised away from the ratchet teeth. and the partialrotation given the ratchet wheel 33 will be less than the rock ingmovement of the lever and counterweight system 34, 35, 36-. It isapparent that a very accurate control and raising of the stack is thusafforded.

When the plungers 15 are raised. the pin 19 will always disengage thelever 20, so that the circuit will be interrupted at the contact points23, 24 and no elevation of the stack can occur except when the plungers15 and the cups 16 are at or-near their lowermost position. In this waythe machine is prevented from raising the stack so high that the rollers17 become disengaged from the cams 18 durin any part of the rotation ofthe latter, whizh may result in a sudden or jerky starting of the upwardmovement of the suctioncups 16, and therewith an engagement of more thanone sheet of the material. It will be understood that the illustrativeform set forth on the drawings and the above description is not by wayof limitation, and that the invention may be practiced in many wayswithin the scope of the appended claims.

What is claimed as new is 1. In a feeder apparatus for the individualsheets of astack, a stack raising-mechanism.

and a source of power for the same, lifting means to engage and liftthetop sheet of .the stack and adapted to move upward" and downwardrelative to the stack and being limited in the downward movement by thetop of the stack, and a stack-raising control v,device including acircuit breaker which is normally open, means to close the circuitbreaker during the time the lifting meansis below a predeterminedposition, a circuit including said circuit breaker, and means controlledby said circuit when closed to connect said and being limited in thedownward move ment thereby, a lever controlling a normally opencontact,a pin on the cup plunger to move the lever to close the contact upon adownward movement of said cup beyond a predetermined position, a circuitincluding said contacts, and means controlled by said circuit whenclosed to connect said source of powerto said mechanism to produce arais ing of'the stack.

3. In a feeder apparatusfor the individual sheets of astack, a platformto support the stack and means to. raise the platform including a shaft,a ratchet fixed to said shaft, a pawl adapted to engage said ratchet tomove the same, a rocker carried by said pawl, a sourc'eo f power andconnections therefrom to move said rbcker; devices including an electriccircuit breaker which is normally open, and means to close said breakerwhen the top of said stack is below a predetermined position, and acircuit including an electromagnet, which 1s energized when said circuitbreaker is closed, and means operated by the said electromagnet whenenergized to permit said pawl to engage and move said ratchet, andoperating when said electromagnet is deenergized to remove said pawlfrom said ratchet.

4. In a feeder apparatus for the individual sheets of a stack, aplatform to support the stack, means to raise s'aid platform including ashaft, a ratchet fixed on said shaft, a pawl adapted to engage saidratchet, a rocker carrying said pawl, a source of power and connectionsfrom the same to move said rocker; an electric circuit breaker which isnormally open and means to closethe same when the top of said stack isbelow a predetermined position, and a circuit including an electromagnetenergized when said circuit breaker is closed; a lever having a guidesurface, a projection on said pawl adapted to slide on said surfacewhensaid lever is in the first position so that the pawl is held out ofengagement with the ratchet, said electromagnet when energized movingsaid lever into said first position so that said pawl is permitted toengage and move said ratchet, and' means operative when saidelectromagnet is deenergized to move said lever to disengage said pawlfrom said ratchet;

5. In a feeder apparatus for the individual sheets of a stack, aplatform to support the stack, means to raise the platform with thestack thereon, and including a shaft, a ratchet fixed on said shaft,lifting means to engage and lift the top sheet of the stack and adaptedto move upward and downward relative to the stack and bein limited inthe downward movement by t e top of the stack, a normally open circuitbreaker and means on said lifting means to close said circuit breakerupon a downward movement of the lifting means beyond a predeterminedposition, a circuit including an electromagnet energized when thecircuit breaker is closed, a pawl adapted to engage said ratchet, arocker carrying said pawl, a source of power and connections from thesame to move the rocker,

a lever having a guide surface and being operated by said electromagnetwhen energized to permit said pawl to engage the ratchet so that thepower transmitted through the rocker and pawl will advance the ratchetand raise the platform, and means to move the lever in the oppositedirectionwhen the electromagnet is deenergized so that the pawl is heldaway from 'the ratchet; whereby the platform and the stack thereon areraised after and when the lifting devices pass below such predeterminedposition.

In testimony whereof, I afiix my signature.

HENRY A. FINK.

